acta ,,_01011108 polonloa Vol. 30, No ... Wa.ruawa 1980 RYSZARD FUGLEWICZ Stratigraphy and palaeogeography of Lower Triassic in Poland on the bassis of megaspores ABSTRACT: The study deals with stratigraphy and correlation of Buntsandstein in the Polish Lowland and in the Tatra Mts on the basis of megaspores. Three key (for Buntsandstein) assemblage megaspore zones were diatingulshed: Otynisporites eotriassicus, Ttileites poloni1!us - PusuIosporites populosus and Trileites validus. Two new species (EchitTtZetes vaIidispinus sp. n. and Nathor8tt­ spontes cornutus sp. n.) were described. An influence of tectonic movements of Pfiilzic and Harc:legsen phases on sedimentation of Buntsandstein was discussed. INTRODUCTION In the paper a lithostratigraphy, a biostratigraphy and a palaeogeo­ graphy of Lower Triassic in the Polish Lowland and in the Tatra Mts are presented. The material for the analyses came from cores of 18 boreholes of Geological Institute, Warsaw and of petroleum · exploration firms at WoIomin and Pila(Fig. 1); among them 11 boreholes were cored in full. Besides, the random samples of nine other boreholes of petroleum exploration firms were used. In the Tatra Mts the samples were taken from exposures of High-tatric Triassic by Z6ua: Tumia and in the valley of Stare Szalasiska as well as from Sub-tatric Triassic in the Jaworzynka valley. During the analysis of these profiles and the confrontation of lite­ rature data the author concluded that within a sequence of Bunt­ sandstein there were almost in the whole area of the Polish Lowlands two oolitic horizons that had originated in result of marine ingressions. Therefore, a previously prepared lithostratigraphical scheme of Poland (Fuglewicz 1973) could be used. On the ground of the same data a map of occurrence of particular Buntsandstein horizons, connected with illgl1'eBSlons (Of l~ttic beds, upper-001iltlic beds and ROt), amid be prepared (Fig. 1). BYSZABD FtTGI&WICZ o 30 60 90 12Il1om Fig. 1. Localization sketCh of analyzed boreholes and exposures and .of extent of some .Buntsandstein horizons (extent of ROt after Senkowiczowa & Szyperko-Sliw- czyilska (1972) with slight modification) . 1 - more important ot ' analyzed borehoJ.ejt, I -' ex:p08l1rel of the LOWer Tri8S&ic tn the Tatra Kts, , - found extent of the lower-ooUt1c bedlI, , - found eztent of the upper-oolWc bedS, $ - extent t BOt, IS - northern border of the Carpathtan overtbnDt . Systematic author's research of megaspores in Buntsandstein deposits in various regions of Poland, carried through. for aver ten years has' been at first unsuccessful but then, effected in good results --in collecting. a rich set of megaspores. About 900 samples were subjected ·to a megaspore analysis; the samples wer~ macerated by the author's improved method (Fuglewicz 1977a). In result of the megaspore analyses 46 new megaspOre' species were palaeontologicaly described (Fuglewicz 1973, 1977, 1979b); among them two species (Echitriletes validispinus sp.n. and Nathorstisporites cornu­ tus sp.n.) are described in the present · paper. Beskles, six megaspore species are included in a "species" category due to a small number of specimens. ~e plates contain mainly the Ulustrations . of these species thaf have been up to now illustrated in a reflected light only \Jut they were succeeded to be photographed with a use of a scanning microscope. The collected megaspore data coming the whole Buntsandstein of PolaDd, alkJwed to distinguish three megaspore zones: a zone Otynis­ porites eotriassicus, guide fossil for the Lower Buntsandstein; a zone Trileites polonicus - Pusulosporitespopulosus, guide fossil for the Middle Buntsandstein, and a zone Trileites validus, . guide fossil for the LOWER TRIASSIC· MEGASPORES 419 Upper Buntsandstein. Within a zone ·0. eotriassicus two subzones were distinguished: lower O. eotriassicus and upper O. eotriassicu.s subzones. Barren complexes were distinguished as intervals. barren intrazones and interzones (Fig. 20). Lithology and megaspore . content of ten most important (full and of best megaspore documentation)· borehole cores · are graphicaly Presented (Fig. 5-14). In full-cored bore~oles the lithostratigraphic and the biostratigraphic borders could be defined in detail whereas in the bor.eholes of control coring these borders were approximate only. A use of a biostratigraphic scale for correlation of BUntsandstein profiles enabled to revise the errors in correlations based on a lithologic method only. The latter refers mainly to a correlation of Buntsandstein deposits of south-western . and north-eastern Poland (Fig. ·4). A mega­ spore analysis was also useful for interpretation of environmental and palaeogeographic conditiOns. A confrontation of lithostratigraphic and biostratigraphic data enabled to find the sedimentary breaks caused by two tectonic phases, PfiUzic and Hardegsen ones, of decisive influence on sedimentation of Bwitsandstein deposits~ · Subsidence, sedimentation and palaeogeography of Buntsandstein"· in POland and probably, in the whole "Central European Basin were proved to be ruled by the contrastive movements of Palaeozoic and Precambrian platforms (Figs 21, 23). Acknowiedgements. The author thanks from .his heart to Profeasor J. Mali­ nowski, the Head of the Gt!ological Institute, Ww:saw and to Docent Dr. A. Wit­ kowski, the chief of Dept. of Regional Geology of Platform Areas for offering the cores for megaspore analyses. I am also indebted to the managers of petro­ leum exploration firms at Wolomin and Pila. I wish also to thank very much to Professor J. Znosko, Professor S. Orlowski . and Professor J. Kutek for their helpful criticism and discussions. Particular thanks are given to Dr. " W. R. Kowalski, for frequent discussions and for a help in preparing the illustrations of this work and to Dr. B. Gaczynski !lnd Mr. A. , Iwa­ now, M.Sc. for their remAl"ks. I would like also to thank Mrs. J. Smolenska; M.Sc. for a final drawing 6f the figures. The · photographs of megaspores were · done with a sca.nning microscope in the Nencki Institute of Experimental Biology, Polish Academy of Sciences, whereas the photographs of other fossils were taken by Mrs. B. Drozd, M.Sc. and Mrs. S. ZieUnska; I thank them both very much. An inappreciable help during preparation of this work was given ·to me by my wife, Dr. B. Jendryka - Fuglewiczto whom I thank particularly warmly. PRESENT KNOWLEDGE OF STRATIGRAPHY OF BUNTSANDSTEIN IN POLAND CA REGIONAL DESCRIPTION) LITHOSTRATIGRAPHIC STUDIES Until 1965 a: traditional subdivision of Buntsandstein. (into lower, middle and upper ones) had been applied for the Polish Lowland with 420 RY8ZABD FUGL&~Z regard to exposures as well as for boreholes (Szubin). Buntsandstein, known from exposures, represents a littoral part of the basip, it is much reduced and contains a great content of coarse-detrital rocks; there are also numerous sedimentary breaks (Fig. 3, also Backhaus 1976). On this basis the first lithostratigraphic schemes have been prepared, similarly as in Germany. The data from the boreholes supplied with Gorz6w Wlelko­ polski IG-t Oty~ IG-! St,5z6w IG-! Czenlcz~ IG-! Lower .. ootitiG bids Fig. 2. Correlation of the bottom border of Buntsandstein taking some boreboles from tbe Fore-Sudetic Monocline as example. Explanations aa at Fig. 4 Mcirgin Fore-Sudetic of the MiechOw Monocline HoIyCross Mts Trough Tatru Mts Ot"; i.apuszn.i \G-' IG·' Fig. 3. Correlation 01 sediments of Middle Buntsandstein in some sections_ Ex­ planations as at Fig. 4 LOWER" TRIASSIC MEGASPORES 421 new, unexpectable information. A thicknesS of Buntsandstein in the Polish Lowland was found to be many times greater than in exposures and the sequences were much more complete. For such sequences a subdivision of" Buntsandstein into lower, middle and upper parts are already unsatisfactory and frequ~tly," d~e to another composition, impossible to be done.. "Among various proposals of Buntsandstein stratigraphy in the Polish Lowland the most consistent and the" most detailed subdivision has been done for the Fore-Sudetic Monocline. FOR!; - SUDETIC AREA "Good cores from that area were obtained in result of bitumen eXploration and were analyzed by Tokarski (1962, 1965), then by Senkowiczowa (1965b) and Sokolowski (1967). Basing on a cycli-c &\1ceession of evaporltic c~plex.es Tokar­ ski (1965) and Senkowiczowa (1965b) prepared independently a Uthostratlgraphical subdivision of ROt. The Senkowiczowa's subdivision, slightly modified was then applied by Fuglewiez (l977b, 1979a, Table 1). Sokolowski (1967) presented a stratigraphic" scheme for the whole Bunt­ sandstein of the Fore~udetic Monocline. Basing on a physico-chemical change­ ability of thesediments and referring to the SUbdivision of ROt by Tokarski, he distinguished 21 "lithologic-Iogging complexes within "the Buntsandstein (Table 1). A great facial changeability of depOsits of Buntsandstein made the Sokolowski's subdivision to be not of a universal significance what has been already noticed Forl-SUd.tlc: Monoc:line East- European Platform Nldzk:. - IG .. 1 c . • . • .. c " • != :I • M-••lllle 11.''11 .itl.... Zleht1.kI Fig. 4. Correlating section of some profiles of the" Buntsandstein of" the Fore-Su- detie Monocli~ and of the north-eastern Poland 1 - co~erate8, 11 -lan4ItOllel, 11 - clayROIlel and I1ltswnea, 4 - marls, 5 - limestones, ," - dolomtte.,"7 -gypsum andanhydrite, B - "Its, • -"- oolitl.c llediments, 10 - stromlito­ lites, li - megasporea, 11 - tectonic "contact, l3" - sedlmentary' dlscontinuitiea, 14 - lOwer